1. Field of the Invention
The present invention relates to resealable beverage containers and methods of making same. In particular, and according to one aspect of the invention, a beverage container such as an aluminum can is provided with a cap that is twisted by the consumer to open the can. The twist or rotational movement of the cap is converted into linear motion by a cam mechanism to drive the cap into opening action, whereby a frangible sealing tab is pushed into the can. Once the can is opened, the cap can be reverse-twisted to remove it from the opening, and then after drinking, the consumer can twist the cap back into a sealing position within the opening.
2. Description of the Related Art
The beverage and can industries have long sought to create a can that is both economical to produce and convenient for use by consumers. In the past, beverage cans were provided with a “pull tab” which the consumer would grab by a ring, and pull until the tab was removed from the can. This created a problem in that the tab became disposable waste for which the consumer was responsible to ensure proper disposal. Often the consumer failed to properly dispose of the tab, thereby creating not only litter, but also a safety issue, in that the tabs could be swallowed by small children. Moreover, the edges of the pull tab were sharp enough that they could, if mishandled, cut the fingers or hands of the consumer or anyone else who handled a loose pull tab. As a result of these problems, the industry moved in the direction of a tab that stayed on the can after opening, thereby preventing both litter and any sharp edges from coming into contact with consumers.
The present state of the art is to have a “stay on” tab that is attached to the can lid by a rivet formed in the can lid next to the opening. The opening is formed by a score line, or frangible “kiss cut” which breaks when the tab is pulled up by the consumer. The score line, when broken, produces a hinged flap that stays connected to the can lid, but inside the can.
Beverage cans with stay on tabs suffer from at least the following deficiencies. First, they are not resealable, so that once the consumer opens the beverage, the contents are subject to loss of carbonation, and the influx of foreign material due to the contents being open to the surrounding environment. Secondly, in order to form the rivet which is used to secure the stay on tab to the beverage lid, the lid needs to be made of a different material, typically an aluminum alloy that is stronger than the aluminum alloy used to make the sides and bottom of the can. Further, the tab itself is typically made of a different alloy than the sides and lid, reflecting the need for a still stronger, typically heavier material. As a result, recycling of the aluminum beverage can is problematic because the different materials need to be separated. The use of three different materials also tends to add weight, and expense, to the finished container.
A need exists for improved beverage containers that are resealable, cost effective to produce, and “green” in terms of avoiding waste and facilitating the recycling of aluminum cans. Concurrently, a need exists for improved methods for manufacturing beverage containers that result in faster production time, lower production costs, and improved products.